Screwdrivers with anti-cam-out tips or ribs (ACR) offer an improved tool-fastener grip that reduces cam-out and potential fastener damage. Less slippage also translates to greater power transmission, and more efficient screwdriving.
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What Makes Them Resist Camming-Out?
Anti-cam-out screwdrivers or screwdriver bits have tips that have either raised ribs or recessed grooves. The edges of these ACO/ACR features dig into the inner walls of fasteners, creating additional friction that helps the driver resist camming-out of the fastener.
Are Anti-Cam-Out Screwdrivers Better than Ordinary Drivers?
Not necessarily, but they absolutely do come in handy when you need an extra bit of grip on a fastener. These days I tend to use ACO/ACR drivers more on slotted screws than Phillips. That’s mostly because I try to use Robertson/square drive screws for most woodworking projects, and hex for most of my other projects.
Phillips screwdrivers are actually designed to cam out from a fastener to avoid applying excessive torque. While I’ve never sheared the head off a screw using a handheld screwdriver, I have damaged plenty of [cheaper/lower quality] fasteners, making their future removal difficult.
ACR drivers are also handy when dealing with partially stripped screwdriver heads. The extra grab they provide can be just enough to loosen a screw before a screw extractor is needed as a last resort.
I use two brands of ACR drivers on a regular basis – 3K ACO drivers from Wiha, and Kraftform Plus drivers from Wera. These days most quality screwdrivers have decent tip coatings that also improve fastener grip, but they’re no substitute for true ACO/ACR grooves.
Wiha Anti-Cam-Out Screwdrivers via Amazon
Wera Kraftform Laser Tip Screwdrivers via Woodcraft
Wera Kraftform Plus 300 Drivers via Amazon
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Product Info via Wera
PutnamEco
What I find, is that there are a multitude of screws that look like they are phillips head screws but in actuality are not. Posidrive, Recex, J.I.S., Frearson, not to mention the many variations of the Phillips brand, Phillips II, Phillips Square-Driv, Phillips Square-Driv 2, ACR Phillips, ACR Phillips Square-Driv, All look like they work with your standard Phillips screwdriver, but they don’t work well.which leads to many people not giving them a fair chance., and condemning them all as easy to strip.
So
Are Anti-Cam-Out Screwdrivers Better than Ordinary Drivers?
Yes, when used with the proper screws, no when they a mismatched to the wrong fastener.
P.S. ACR is a registered trademark of a very specific screw type, won’t work as well in a plain phillips head screws as they will in ACR screws.
P.P.S. You also have to be aware that a true Robertson has a slight taper and a square drive does not. I have seen this bite a few people as well, them blaming it on the fasteners instead of their own misuse of the wrong driver.
BRIAN CHILES
Do you have any stocking distributers for anti cam out bits in Edmonton Alberta Canada
Thanks
Brian
Nathan
I have a few basic screwdrivers – they are stahlwille, but I hardly ever use them.
I use bits in a ratcheting or other type driver and a few bits I’ve seen are ACO philips.
would like to know of some good ones to get. for wood screws at home I like the the max fit bits from dewalt only because they have that nifty magnet piece.
Chunkyboy
Am sure that the ribs would help but what has more impact on performance is the basic shape and durability
Have a phillips from picquic which never cams out because the shape is right and the metal is friggin hard 🙂